<?php
/*
 * Copyright (c) 2011 Antoine d'Otreppe de Bouvette
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
 * IN THE SOFTWARE.
 */

class FileLogger extends AbstractLogger {
    private $filename;

    public function __construct($filename) {
        if ($this->isValidFile($filename)) {
            $this->filename = $filename;
        }
        else {
            throw new RuntimeException(
                    "The given log file cannot be written to: $filename");
        }
    }

    private function isValidFile($filename) {
        return (is_file($filename) && is_writable($filename)) ||
                is_writable(dirname($filename));
    }

    protected function log($message) {
        file_put_contents($this->filename, $message, FILE_APPEND);
    }
}
